linqpad - SubmitChanges 扩展

Question

是否可以让 SubmitChanges() 在扩展方法中工作？

我目前有这个：

void Main()
{
    // Write code to test your extensions here. Press F5 to compile and run.
    Helper.ConfirmSubmitChanges();
}

public static class Helper
{
    // Write custom extension methods here. They will be available to all queries.
    public static void ConfirmSubmitChanges() 
    { 
        if (MessageBox.Show("Save?", "Do you really want to save all changes?", MessageBoxButtons.YesNo, MessageBoxIcon.Question) == DialogResult.Yes)
        {
            SubmitChanges(); 
        }
    }
}

// You can also define non-static classes, enums, etc.

但是 SubmitChanges() 在这里脱离了上下文。我可以从我的查询中传递什么内容来使用此扩展来使其工作吗？

谢谢， 科汉

Answer 1

您可以通过将当前上下文 (this) 传递到静态方法中来完成此操作：

您的程序：

void Main()
{
    //Do Stuff  
    ConfirmSubmitChanges(this);
}

在 My Extensions.linq 中：

static void ConfirmSubmitChanges(DataContext context)
{
    if (MessageBox.Show("Submit Changes?", "OK?", MessageBoxButtons.YesNo) == DialogResult.Yes)
    {
        context.SubmitChanges();
        "Saved".Dump();
    }
}

Answer 2

如果有人想知道，请将“this”传递给扩展程序后。这就是我最终创建的。这很好，因为它还确认了更改的数量。

#region ConfirmSubmitChanges(DataContext dc)
public static void ConfirmSubmitChanges(DataContext dc)
{
    ConfirmSubmitChanges(dc, string.Empty);
}

public static void ConfirmSubmitChanges(DataContext dc, string AdditionalMessage)
{
    ChangeSet set = dc.GetChangeSet();
    var countChanges = 0;
        countChanges += set.Deletes.Count();
        countChanges += set.Inserts.Count();
        countChanges += set.Updates.Count();

    if (countChanges>0) {
        if(!string.IsNullOrEmpty(AdditionalMessage)) { AdditionalMessage = "\n\n(" + AdditionalMessage + ")"; }
        if (MessageBox.Show("Do you really want to save "+ countChanges+" changes?" + AdditionalMessage, "Save all changes?", MessageBoxButtons.YesNo, MessageBoxIcon.Question) == DialogResult.Yes)
        {
            dc.SubmitChanges();
        }
    }
}

#endregion